Hey guys, thanks for your replies as regards my posts here. I'm currently facing a terrible challenge with a Prius. The car was driven to the parking lot, then suddenly, there was loss of power. Some kind of hesitation. We trued starting the car, it couldn't. The dash lights all came on, except the CHECK ENGINE SIGN(ECU). That made me to think that there could be power issues with the ECU. Techstream could not scan the engine side of the car, because there was no check light on. Did a general Heath check, and got the following codes: C1201 U0073 U0100 U0101 U0142 U0155 B2788 C1201 I'm suspecting the ECU isn't communicating with the CAN. Has the ECU failed or what? Thanks for your replies.
Before doing anything else, check the voltage on your 12 volt accessory battery (NOT the large traction battery). If that goes low, it can cause all sorts of lights and codes because the ECUs can't communicate properly. That's the place to start. Good luck!
That is effectively DEAD. Exactly how "new" is it ? Was it charged from an external source before being installed ?? Who installed it ? Anyhow, now it needs to be thoroughly charged with an external charger. With a small, maintenance charger that might take as much as 24 hours. With a standard 6 to 10 amp charger, maybe 6 to 8 hours. You do not have to remove or disconnect the battery to do this charging.......but you should NOT try to start the car until the charging process is done.
Want to thank everyone for your contributions. The issues has being resolved. Problem was the ECU power source from the engine fusebox, got burnt, and had to be repaired. Now all lights are functioning normally, as they should. Regards to everyone
Having the most obvious symptoms fixed does NOT change the fact that this measured battery voltage is WAY too low. You NEED to check that out too. If you don't, you might be sorry.......and very soon too.
Do anyone with issues like these, should first of all follow start from the least to the complex troubleshooting procedure. 1. Check fuses and relays 2. ECU and fuselage wire harnesses 3. Carry out resistance, continuity and voltage tests on related wiring circuits for shorts/opens. Atleast that was what I did in my case. Discovered it was the ECU power source that had an open in the ECU harness circuits.
Would car Would carry out a battery analyzer test on it later and see how it performs. Meanwhile, I'm kind of like testing the car first.
Even the best "battery analyzers" sometimes will not catch a marginal low voltage condition. And most of the testers in use are not the best. IF......you continue to measure a battery voltage below 12.0 volts, SOMETHING is wrong. If it stays that low while the car is in "ready" mode (running) then the charging system is not working.
Wao! An eye opener for me here. I think the best solution to situations like these, is to ensured batteries are procures from reputable brands.
Even the best things ever made sometimes fail in actual use. But yes, getting a brand that has a good reputation should give you a better chance of not having a problem.
